swansont

Absent some outside interaction, the moon will not escape from the earth, since it is gravitationally bound. The current situation, of receding ~ 4cm per year, is transfer of energy and angular momentum because of tidal interactions ("tidal friction"), which is responsible for the slowing of the earth's rotation and the main reason we have leap seconds. Once the earth becomes tidally locked to the moon, they will face each other with no relative rotation, and the moon will not recede anymore. At that point, energy losses will cause the moon to get closer to the earth.

Heat is a form of energy (transfer) and temperature is one way that the enegy of compression or expansion will manifest itself. There are a number of places energy can be stored. You have to specify the conditions, e.g. isothermal, adiabatic and go from there. The basic idea is that PV is an energy term. The rest tells you, though, that doubling the pressure may require more than twice the energy to get there. And if you want to do work with the PV term, you will be able to use differing amounts of it, depending on how the expansion takes place. (Also, in Bernoulli's equation you get [math]P + \rho gh + \frac1 2 \rho v^2[/math], which has a volume term divided out, so there's a PV term there, too. But that equation assumes certain things, like incompressible fluids and (IIRC) isothermal conditions)

I think they should have used the Mobius strip more to show the folding concept, and tried to explain a Klein bottle.

I think it's too vague to tell for sure, since it's not meant to be rigorous; I think you can take it either way. If there are multiple possible outcomes, yet you know the relative probabilities, is the system unpredictable? Depends on how you define the term, and the term wasn't defined there.

A search of the MIT site shows that name and email address as an affiliate. This page implies that an affiliate is the spouse/partner of an MIT student or employee.

Found a nice post of things to keep in mind for anyone thinking they've overturned modern science. Some old, some new. http://insti.physics.sunysb.edu/~siegel/quack.html

Found a nice post of things to keep in mind for anyone thinking they've overturned modern science. Some old, some new. http://insti.physics.sunysb.edu/~siegel/quack.html

Gotta go with the experimental evidence. Einstein's quote is from before the Bell inequality experiments, and Hawking's is from a book for a lay audience. "It does not make any difference how smart you are, who made the guess, or what his name is - if it disagrees with experiment it is wrong." Feynman

Oh dear. What would Sigmund say?

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thepot.html#c1

That depends on how much of the effect is from the object itself and how much from terrestrial debris from the impact. If the terrestrial debris is a significant effect, then the more surface area of the object you expose, the better off you are. You want to decrease the net impact energy. Terminal velocity varies as sqrt (Weight/Area), so the associated kinetic energy varies linearly. And W decreases faster than A as you get smaller (cube vs square dependence). And that's not even looking at the loss of material due to ram pressure heating; more exposed surface area should burn away more material prior to impact.

Seems to me that you have only so many degrees of freedom. If some parameters are fixed, you have fewer degrees for the remaining ones. There is only one reality, after all.

You can do both. At the same time.

But that's one strategy. Smaller objects would be more likely to burn up in the atmosphere.

As BhavinB said, it's always a measurement with regard to some reference. There is no such thing as an absolute length measurement, according to relativity.

But you haven't done that, and changing measurement techniques is only untenable if there is a bias between them. You say that the measurements are "pretending" to be comparable; did Mann calibrate the measurements or not? I don't see a discontinuity in the data, which is one thing you might expect if the two techniques were not comparable. And you still haven't addressed the issue of the geographical area of the data. If you are using a local measurement to compare to a global one, it means nothing. You can have local behavior that is different than the global. This applies to the glacier data as well.

So where, exactly, am I wrong? You haven't provided a scientifically valid criticism. You have only provided a graph of tree growth measurements. And the temperature calibration wasn't the only limitation I mentioned. I can get (I provided a link before, in the other thread) the temperature data for regions of the US that show that parts of it have cooled over the last 100 years. Does that prove that world hasn't warmed up? So local vs global has to be addressed as well. It's too bad you see this as arrogance. The objection you have presented, scientifically, is crap. That doesn't make the Mann curve right, but I've never argued that point, anyway. Your glacier graph was way too small to read. Doesn't it exist online somewhere else?

Rubbish. Your second graph doesn't have a temperature scale. It is in units of mm. Without a calibration' date=' you can't say anything about the temperature range present in the lower graph. Surely you know that correlation doesn't mean causality; it insufficient that the method changed at that point. Again, without knowing how tree-ring growth is related to temperature and other environmental parameters, none of the conclusions you have presented are valid. Is it linear? What if it's quadratic, or exponential? What if it also depended on, oh, rainfall, for example? Is it a local measurement, or a global one? (local areas can show different trends than the average). None of those factors are addressed, and they are all relevant. Without that information, you can't draw any conclusion about what the graph means, other than what it says: tree growth (for whatever data sample was used) has shown variation over time. Your concern about the Mann graph is valid. A change in method is something that should be investigated. But you haven't presented a scientifically valid contradiction to it. Did Mann address that concern in the original literature? I know of other experiments where the dynamic range of an apparatus is insufficient to collect all the data you want, so that multiple methods have to be used; it's no problem if you calibrate your detectors, so it's not something that automatically invalidates the measurement.

But you haven't actually demonstrated that. You need evidence. Show the calibration for the tree-growth curve, show that it's global data and not local, and then you're on to something. But until that or similar evidence is presented, you simply can't draw the conclusion that you have.

Perhaps. But remember that "fudging" also led to the discovery of the neutrino.

Copenhagen, as far as you can go with philosophy describing science. It might tell you how to look at a problem, but debates about "what is the true nature of QM" (much like the "nature of time" debates) are always going to come up short of real answers. Seems to me it's more a way of getting used to the ideas that differ from what everyday macroscopic experiences tell us.

Already being discussed. http://www.scienceforums.net/forums/showthread.php?t=21866

A number of cars didn't hit me this morning, even though they were close to me. Stop the presses! It missed us. The people tracking it knew it was going to miss us. So, no big deal. Nothing happened. Hooray for Newtonian physics. The reason there are unkown ones is that you find them by seeing things moving in the sky, but an object heading straight toward us doesn't move relative to the background stars (only parallax will show anything). If it's small, it won't reflect much light and would be hard to see util it's fairly close. And, as i_a said, space is big. (As Douglas Adams put it, "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.")

The Skeptical Inquirer's take.